In irradiating the insulation of cable with an electron or other beam, in order to affect the insulation or its properties in a desired manner, such cable is customarily passed into a shielded chamber which houses the beam. The cable travels longitudinally, entering the chamber at one aperture therein and exiting through a second aperture therein.
Normally, it is not desirable or safe to permit the radiation outside the chamber to exceed a certain level.
It is, therefore, important to prevent the greatest portion of radiation from escaping the chamber.
In addition, where cable is rotated as it passes through the chamber, it is also important that the cable be adequately supported to prevent catenary effects especially where the cable is struck by the beam.